Objectives: To observe the effect of moxibustion of "Feishu"(BL 13) and "Gaohuangshu"(BL 43) on the balance of T helper1/T helper2(Th1/Th2) cytokines in BLM_(A5)-induced pulmonary fibrosis rats

and to explore its underlying mechanism.Methods: Twenty-four SD rats were evenly randomized into control

model

moxibustion

and medication groups.Pulmonary fibrosis model was established by injection of Bleomycin via trachea(5 mg/kg).Moxibustion(3 cones/acupoint) was applied to bilateral "Feishu"(BL 13) and "Gaohuangshu"(BL 43)

once daily

with 10 days being a therapeutic course and an interval of one day

3 courses altogether.Rats of medication group were fed with Prednisone(2.5 mg/kg)

once daily and continuously for 30 days.At the end of experiments

the rats were killed for taking out the left mid-lung tissues to be processed into homogenate samples.Cytokines such as IL-2

IL-12

IL-4 and IL-5 were detected with enzyme linked immunosorbent assay according to instructions of reagent kits.Results: In comparison with control group

IL-2 and IL-12 contents of the lung tissue were significantly lower

while IL-4 and IL-5 considerably higher in model group(P<0.01);whereas compared with model group

IL-2 and IL-12 contents were significantly higher(P<0.05

0.01)

IL-4 and IL-5 levels significantly lower in moxibustion and medication group(P<0.01).No significant differences were found between moxibustion group and medication group in the 4 indexes(P>0.05).It indicated that in BLM_(A5)-induced pulmonary fibrosis rats

Th1 cytokines IL-2 and IL-12 levels in the lung tissue decreased markedly

and Th2 cytokines IL-4 and IL-5 levels increased abnormally

both moxibustion and Prednisone could regulate changes of Th1 and Th2 cytokines.Conclusion: Moxibustion of "Feishu"(BL 13) and "Gaohuangshu"(BL 43) can raise the contents of Th1 cytokines(IL-2 and IL-12) and lower those of Th2 cytokines(IL-4 and IL-5)

suggesting that moxibustion induced balance between Th1 and Th2 cytokines may contribute to its action in resisting pulmonary fibrosis.